“Sharknado” hasn’t yet jumped the shark with viewers, as Syfy’s sequel to last year’s creature feature drew a sizable crowd of 3.9 million viewers on Wednesday night — dwarfing the original’s total, according to Nielsen’s “live plus same-day” estimates.

“Sharknado 2: The Second One,” in which Ian Ziering and Tara Reid return to battle a Sharknado unleashed on New York City, gave the network its most-watched original movie ever.

SEE ALSO: Twitter Much Bigger for ‘Sharknado 2’

By comparison, the NBCUniversal cabler averaged 987,000 viewers in primetime for the first four weeks of July. And in recent years, its biggest recent movie prior to last night was “Swamp Shark,” which gobbled up about 2.2 million in June 2011.

In adults 18-49, “Sharknado 2” averaged about 1.6 million viewers — nearly triple what the original attracted — and outdrew Wednesday broadcast originals like “Extant,” “Motive” and “So You Think You Can Dance.”

The first installment of “Sharknado” was a tsunami on Twitter — peaking at about 5,000 tweets per minute during its premiere airing last July on Syfy — but drew a modest 1.37 million “live plus same-day” viewers. A couple of subsequent replays actually fared better, and Syfy estimates that more than 14 million Americans ended up catching at least a few minutes of the film.

According to Nielsen Twitter ratings, there were 581,000 tweets about the movie during its premiere — 83% more than the original (318,000). At several points during the movie, nine of 10 U.S. trending topics on the social media platform were related to “Sharknado.”

“Sharknado 2,” directed by Anthony C. Ferrante from a screenplay by Thunder Levin, also stars Mark McGrath, Kari Wuhrer, Vivica A. Fox and Judah Friedlander, with cameo appearances by Kelly Osbourne, Judd Hirsch, Perez Hilton, Matt Lauer, Al Roker and Andy Dick.